Device For Attaching An Element To A Holder

ABSTRACT

Device for attaching an element ( 20 ) to a holder ( 22 ) comprising a screw ( 4 ) including a body ( 10 ) and a head ( 8 ), intended to pass through an opening ( 24 ) of the element ( 20 ) and to penetrate the holder ( 22 ), and a washer ( 6 ) intended to surround the screw ( 4 ) while being inserted between the head ( 8 ) of the screw and the element ( 20 ). 
     The washer ( 6 ) comprises an external periphery ( 14 ) and an internal periphery ( 16 ) each having at least one protruding portion ( 30, 32 ) intended to penetrate respectively the element ( 20 ) and the holder ( 22 ) to provide the attachment. 
     Attachment method using such a device. 
     Front face with a such device. 
     Application to motor vehicles.

The invention relates to a device for attaching an element to a holder.

More particularly, the invention relates to such a device of the type comprising a screw including a body and a head, intended to pass through an opening of the element and to penetrate the holder, and a washer intended to surround the screw while being inserted between the head of the screw and the element.

The invention particularly finds its application in the attachment of the headlights of a vehicle to a front face. A front face is a structural element likely to incorporate various items of equipment of a vehicle, such as headlights, indicator lights, audible warnings, heat exchanger, fan-motor group, or complete cooling module, etc.

The module, thus provided with its items of equipment, forms a unitary element prepared and delivered by the equipment supplier, ready to be mounted on the vehicle by the manufacturer. This unitary module is installed by connection to lateral structural elements of the vehicle, such as the chassis rails, wings or body shells, then installation of a bumper or front protective fender fitted to the module.

The mounting of the headlights on a front face is usually a lengthy and costly process. Attachment is usually provided by self-tapping screws, in plastic bushes of the holder. In order to ensure that this assembly holds, anti-creep rings that are made of metal are usually added. On these rings, there are small teeth which plant themselves in the holder to increase the mechanical hold.

The mounting of the headlights comprises the following steps:

-   -   mounting of the rings onto the headlight;     -   crimping of the rings for a provisional hold;     -   preparation of screws with captive washers;     -   setting of the headlights with reference to the front face; and     -   tightening.

The object of the invention is particularly to improve the situation.

For this purpose the invention proposes a device for attaching an element to a holder comprising a screw including a body and a head, intended to pass through an opening of the element and to penetrate the holder, and a washer intended to surround the screw while being inserted between the head of the screw and the element. The washer comprises an external periphery and an internal periphery each having at least one protruding portion intended to penetrate respectively the element and the holder to provide the attachment.

Such an attachment device is particularly valuable in that it offers an excellent mechanical hold thanks to the respective penetration of the element and the holder via the protruding portions. This attachment device however remains extremely simple, since all that is required is to insert the washer between the head of the screw and the element as for a conventional screw.

In one embodiment, the internal periphery and the external periphery of the washer each comprise portions forming teeth to penetrate respectively the element and the holder.

In a first variant, the teeth may be formed by cut out and reshaped portions of the washer. In another variant, these teeth may be formed by the stamped portions of the washer. In yet another variant form, the internal periphery of the washer comprises a collar forming the protruding portion.

These variants make it possible to produce devices of varied attachment, offering different and effective technologies.

The invention also relates to a method of attaching an element to a holder, comprising the supply of a device as hereinabove, and also comprising the placement of the element relative to the holder, the mounting of the washer onto the screw, the mounting of this assembly through an opening of the element and into the holder and the tightening of the screw until a sufficient degree of attachment is achieved.

The invention also relates to a front face comprising a device for attaching an element to a holder as described above.

Other features and advantages of the invention will better appear on reading the following illustrative and non-limiting description of examples based on the figures in the appended drawings in which:

FIG. 1 represents a view in schematic section of an attachment device according to the invention;

FIG. 2 represents a variant of the device of FIG. 1; and

FIG. 3 is an enlargement of a portion of FIG. 2.

As can be seen in FIG. 1, a device 2 according to the invention comprises a screw 4 and a washer 6. The screw 4 comprises a head 8 and a body 10 furnished with a thread 12. The washer 6 has a substantially annular shape and comprises an external periphery 14 and an internal periphery 16. The attachment device 2 is formed by the assembly of the screw 4 and the washer 6, the body 10 penetrating an opening 18 of the washer 6.

In order to attach an element 20 to a holder 22, the element 20 is placed on the holder 22 so that an attachment opening 24 of the element 20 is substantially opposite a receiving opening 26 of the holder 22. In the example described herein, the opening 24 is substantially larger than the opening 26. In practice, these two openings may be of substantially equal size.

In order to attach the element 20 to the holder 22, the device 2 comes to pass through the attachment opening 24 and penetrate the receiving opening 26. In order to ensure the mechanical hold of this assembly, the screw 8 is screwed into the opening 26, and the tapping provides a hold.

The external periphery 14 and internal periphery 16 of the washer 6 each comprise a pair of respective teeth 30 and 32 which will come to supplement the hold provided by the tapping 12. Specifically, the washer 6 is provided such that it covers the opening 24, irrespective of the position of this opening 24 relative to the opening 26. Thus, the head 8 of the screw 4 which presses on the washer 6 flattens the element 20 onto the holder 22.

In addition, the teeth 30 and 32 of the washer 6 are orientated respectively towards the element 20 and the holder 22, so that they penetrate them when the screw 4 is tightened. The element 20 is then therefore held attached to the holder 22 first by the pressure of the screw 4 on the washer 6 and, secondly, by the teeth 30 and 32 respectively penetrating the element 20 and the holder 22.

In addition, in order to simplify the mounting of the device, the washer is provided to have an internal diameter that is slightly less than that of the body 10 of the screw 4. It thus forms a washer called a captive washer which makes assembly easier. Practically, in a first step, the washer 6 is mounted on the body 10 and the former remains in place spontaneously thanks to this feature.

The attachment of the element 20 to the holder 22 therefore then consists of mounting the washer 6 on the screw 4, mounting this assembly through an opening 24 of the element and in the holder and tightening the screw 4 until a sufficient degree of attachment is achieved.

The teeth 30 and 32 may be formed by cutting out a portion of the external periphery 14 respectively internal periphery 16 of the washer 6 and then reshaping these cut out portions. These teeth may also be formed by local stamping of the external periphery 14 or internal periphery 16 of the washer 6.

FIG. 2 shows a variant of FIG. 1 in which the teeth 32 are replaced by a collar 34 formed in the region of the internal periphery 16 of the washer 6. This collar 34 may in particular be produced by a stamping or a punching of the washer. Provision is made for this collar to be thinner than the washer. When the device 2 is mounted to provide the attachment, the collar 34 plays a role similar to that of the teeth 32.

In this figure, the washer 6 also comprises a set of ridges 36 mounted between the top face of the washer and the head 8 of the screw 4. These ridges 36 are detailed in FIG. 3.

As can be seen in FIG. 3, the ridges 36 are such that a rotation of the head 8 in the direction of the arrow V is not hampered, whereas a rotation of the head 8 in the direction of the arrow D, once the screw 4 has been tightened, is impeded. Thus, once the screw has been mounted and tightened, the teeth 36 make loosening particularly difficult. The ridges 36 therefore make it possible to offer an improvement of the mechanical hold of the device 2, by preventing the screw 4 from loosening. In a particular variant, the ridges “6 can be replaced by a self-locked washer.

In these two embodiments, the respective height of the teeth 30 and 32 and that of the collar 34 may be modified as a function of the element 20 and the holder 22. Specifically, according to the depth of the opening 24 and the respective hardness of the element 20 and the holder 22, the variation in the respective height of the teeth 30 and 32 (and of the collar 34) makes it possible to choose whichever of the pairs of teeth will penetrate first and the depth of this penetration. By dimensioning these heights it is therefore possible to ensure that the teeth penetrate substantially at the same time, which provides a more precise attachment. Moreover, the control of these dimensions also makes it possible to limit any creep due to the penetration of the teeth 30 and 32 and of the collar 34 into the element 20 and the holder 22.

The description of the examples hereinabove is given as an illustration and is non-limiting and those skilled in the art will be able to envisage any possible variant, particularly on reading the following appended claims. 

1. Device for attaching an element (20) to a holder (22) comprising a screw (4) including a body (10) and a head (8), intended to pass through an opening (24) of the element (20) and to penetrate the holder (22), and a washer (6) intended to surround the screw (4) while being inserted between the head (8) of the screw and the element (20), characterized in that the washer (6) comprises an external periphery (14) and an internal periphery (16) each having at least one protruding portion (30, 32; 30, 34) intended to penetrate respectively the element (20) and the holder (22) to provide the attachment.
 2. Device according to claim 1, characterized in that the washer (6) has an internal diameter substantially less than the diameter of the screw (4), so as to provide a captive connection between the screw (4) and the washer (6).
 3. Device according to one of the preceding claims, characterized in that the external periphery (14) of the washer (6) comprises locally cut out and reshaped portions forming teeth (30) to penetrate the element (20).
 4. Device according to one of claims 1 and 2, characterized in that the external periphery (14) of the washer (6) comprises locally stamped portions forming teeth (30) to penetrate the holder (22).
 5. Device according to one of the preceding claims, characterized in that the internal periphery (16) of the washer (6) comprises locally cut out and reshaped portions forming teeth (32) to penetrate the holder (22).
 6. Device according to one of claims 1 to 4, characterized in that the internal periphery (16) of the washer (6) comprises locally stamped portions forming teeth (32) to penetrate the holder (22).
 7. Device according to one of claims 1 to 4, characterized in that the internal periphery (16) of the washer (6) comprises a collar (34) substantially thinner than the washer (6), surrounding the body (10) of the screw (4) and intended to penetrate the holder (22).
 8. Device according to one of the preceding claims, characterized in that the internal periphery (16) of the washer (6) comprises ridges (36) facing the head (8) of the screw (4), to prevent a rotation of the latter allowing unscrewing.
 9. Device according to one of the preceding claims, characterized in that the protruding portions (30, 32; 30, 34) of the internal periphery (16) and of the external periphery (14) of the washer (6) have respective heights chosen in order to penetrate substantially simultaneously the element (20) and the holder (22) respectively.
 10. Device according to one of the preceding claims, characterized in that the protruding portions (30, 32; 30, 34) of the internal periphery (16) and of the external periphery (14) of the washer (6) have respective heights chosen in order to limit any creep due to their penetration in the element (20) and the holder (22).
 11. Method of attaching an element (20) to a holder (22) comprising the supply of a device (2) according to one of the preceding claims, and also comprising the placement of the element (20) relative to the holder (22), the mounting of the washer (6) onto the screw (4), the mounting of this assembly through an opening (24) of the element (20) and into the holder (22) and the tightening of the screw (4) until a sufficient degree of attachment is achieved.
 12. Front face comprising a device for attaching an element (20) to a holder (22) according to one of claims 1 to
 10. 